Naked Science Forum

Non Life Sciences => Physics, Astronomy & Cosmology => Topic started by: seth on 15/07/2008 02:43:20

Title: Does the moon exist outside of the Hill radius of the earth?
Post by: seth on 15/07/2008 02:43:20

Does the moon exist outside of the Hill radius of the earth?

Title: Re: Does the moon exist outside of the Hill radius of the earth?
Post by: DoctorBeaver on 15/07/2008 07:51:07

No, it is a long way inside.

The Moon is approximately 0.4 million km from Earth and the Earth's Hill radius (also known as the Roche radius) is 1.5 million km.

Title: Re: Does the moon exist outside of the Hill radius of the earth?
Post by: Soul Surfer on 15/07/2008 09:29:45

To clarify this question to general readers.  The Hill radius of the earth is the distance at which the gravitation of the earth controls the motion of an object orbiting the earth.  It essentially means that it is the distance at which the as one moves in orbit with the earth towards the sun that the grvitational influence of the earth is stronger than that of the sun.

Title: Re: Does the moon exist outside of the Hill radius of the earth?
Post by: lyner on 15/07/2008 11:18:04

SS
You might swap the word 'controls' with the word 'dominates'. We all have some effect on each other.